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EXHIBIT 4.A.7
 Execution Copy
 
 SIXTH SUPPLEMENTAL INDENTURE
 among
 EL PASO EXPLORATION & PRODUCTION COMPANY,
 as Issuer,
 MBOW FOUR STAR CORPORATION,
 EL PASO EXPLORATION & PRODUCTION MANAGEMENT, INC.,
 EL PASO E&P HOLDINGS, INC.,
 EL PASO E&P COMPANY, L.P.,
 EL PASO PRODUCTION RESALE COMPANY,
 EL PASO ENERGY OIL TRANSMISSION, L.L.C.,
 EL PASO PRODUCTION OIL & GAS GATHERING, L.P.,
 EL PASO E&P INTERNATIONAL HOLDING COMPANY,
 EL PASO PREFERRED HOLDINGS COMPANY
 and
 EL PASO E&P FINANCE COMPANY, L.L.C.,
 as Subsidiary Guarantors,
 and
 WILMINGTON TRUST COMPANY
 as Trustee
 
 October 1, 2006
 
 73/4% Senior Notes due 2013




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SIXTH SUPPLEMENTAL INDENTURE
 Sixth Supplemental
Indenture Company MBOW Four Star El
Paso Management El Paso Holdings El Paso E&P El Paso
Resale El Paso Transmission El Paso Gathering El Paso International El Paso
Preferred Holdings El Paso Finance Subsidiary Guarantors Trustee
 W I T N E S S E T H:
 El Paso Production GOM Vermejo Raton Original Indenture 3 4 Notes
 Raton Corporation
 First Supplemental
Indenture
 Second Supplemental
Indenture
 Medicine Bow MBOW Operating Third Supplemental Indenture
 1




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Fourth Supplemental Indenture
 Fifth Supplemental Indenture
  Indenture
   2




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ARTICLE 1
 Section 1.01
 Section 1.02
 ARTICLE
 Section 2.01 New Subsidiary Guarantors
 ARTICLE
 Section 3.01
 Section 3.02
 3




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Section 3.03 THIS SIXTH SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.
 Section 3.04
 Section 3.05
  4




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Issuer:
EL PASO EXPLORATION & PRODUCTION COMPANYBy:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerSubsidiary Guarantors:
MBOW FOUR STAR CORPORATIONBy:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerEL PASO EXPLORATION & PRODUCTION MANAGEMENT, INC.By:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerEL PASO E&P HOLDINGS, INC.By:
    /s/ Karen T. SeverinoKaren T. SeverinoVice President and SecretaryEL PASO E&P COMPANY, L.P.By:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial Officer Signature Page to Sixth Supplemental Indenture




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EL PASO PRODUCTION RESALE COMPANYBy:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerEL PASO ENERGY OIL TRANSMISSION, L.L.C.By:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident, Controller and Chief Financial
OfficerEL PASO PRODUCTION OIL & GAS GATHERING, L.P.By:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerEL PASO E&P INTERNATIONAL HOLDING COMPANYBy:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerEL PASO PREFERRED HOLDINGS COMPANYBy:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial OfficerEL PASO E&P FINANCE COMPANY, L.L.C.By:
    /s/ Dane E. WhiteheadDane E. WhiteheadPresident and Chief Financial Officer Signature Page to Sixth Supplemental Indenture




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Trustee:
WILMINGTON TRUST COMPANY, as TrusteeBy:
    /s/ Steven CimaloreName:
    
    Steven CimaloreTitle:
    
    Vice President Signature Page to Sixth Supplemental Indenture